Hardness testing device



April 1933- R. A. WEBSTER 1,903,524

' HARDNESS TESTING DEVICE Filed April 17, 1929 Jmmtoc;

RA. fibxsten CLL.\M-Ia eflicient ty e of device whereb Patented Apr. 11,1933' 'umrno s'r-A'ras PaTENT oarce noraar a. or san raiaomca.

maxim TESTING DIVIGI Application fled April 17, 1.989. SerialI'm-858,788.

This invention relates to a device or tool for testing the hardness ofmaterials, particularly metals, and oneob'ect of the invention is toprovide a simp e, reliable and degrees of hardness 0 a metal withincertain limits may be easily and rapidl determined,

Another object o the invention isto provide a device or tool of thecharacter described which is adapted for-gauging certain degrees ofhardness within certain toleration limits for each degree and to thusserve asa nick and convenient go or no go gauge or the p Stillanotherbbject of the invention to provide a hardness-tester which isadjust able within determined ranges to uge .different specifiedrelative degrees 0 hardness, mployinga particular degree, arbitra o'rotherwise, as a basis of calculation, an in which, interchangeablecombinations of parts may be used to adapt the tool for testing varyingdegrees of hardness within difl'erent hardness-degree ranges. g

With these. and other objects in view,

7 which will appear in the course of the subjoined description, theinvention consists of the features of construction, combination andarrangement of parts, hereinafter full so described and claimed,reference being ha tothe accompanying drawing in which Fig. 1 is a sideelevation of one form of tool embodying the invention.

Fig. 2 is a similar view ofthe jaws of the tool, showing one of the jawsand the s23;-v

porting bracket applied thereto in longitu nal section.

Fig. 3 is a vertical transverse section on line 3-3.of Fig. 2 showingthe impression plunger in end elevation.

Figs. 4, 5 and 6 are sectional views through a piece of sheet materialshowing indicating marks made by the penetrator in tests upon relativelyhard, medium and soft materials.

Referring now particularly to Figs. -1 to 6, inclusive, of the drawing,1 denotes the impression member of the tool and 2 means for supportingthe impression member and backing the material being tested and foractuating the said impression member. The said i and backing t means forsupfiorting the impression member e material and actuating the1111813688101! member may v an assume any form suita le for the. purse,but, as shown in the present instance,

is in the general form of-a air of parallel motion 'pliers embodying ecrossed and pivotally connected actuating handles 3 and 4 carrying thepivotall mounted parallel tween the o posed faces of these jaws the workor materia 7 to be testedis designed to be laced, the jaw 5 serving asan anvil or ba the work, while the jaw 6 serves as a support for theimpression member 1. The face 8 of the jaw 5 on which the work rests ispreferably transversely curved or rounded to adapt motion jaws 5 and 6.

it for backin flat orround (includingtubu-. lar) (pieces 0 material tobe supported and plurality of penetrating teeth or projectionsterminating at difierent levels. In the present instance the penetratingedge is shown as having three marking pro ections consi of a singlecentral tooth or projection 1 having t e greatest extent of projectionor arranged at the lowest level, a air of outer teeth or projections 12arran equidistant ly on opposite sides of the eentraltooth and havingthe least extent of pro ection or at ranged at the highest'level andconjointly forming a marking surface arra at the highest level, and apair of into iate teeth or projections 13 arranged between the tooth 11and the respective teeth 12 and having a median extent of projection orarranged at a level between the levels of the teeth 11 and 12 andconjointly forming a marking sur-- face disposed at an intermediatelevel.

The jaw '6 has a lower plane surface beyond which the marking edge ofthe penein construction ng support for.

trator plunger projects. Suitable means, such as a pin, key or featherMen the jaw 6 and engaging a, groove in the plunger body, is'providedfor preventingrotation of the plunger and maintaining the markingedgeparallel with the jaw, and 'a collar or stop abutment 16 on-theplunger isengageable with an abutment or stop surface 17 on the 'aw 6 tolimit the downward movement of t e plunger. To the Jaw'6 is secured abracket or frame member 18 having a thread-.

plunger an surroundingsaid stem between the collar 16 and the lower endof the sleeve 20 is a coiled backing spring 23 for the plunger, the loadof which on the plunger, or the resistance of which to an upwardyielding movement of the plunger, may be varied by adjustment ofthe'sleeve 20. This ar-= rangement of the plunger, spring and sleeve(load varying member) is, of course, not essential, as any othersuitable arrangement of the same or equivalent parts may be em-r plo ed,and the form and construction of suc parts may be modified or changed atwill so long as the workin principle of the invention is preserved A sothe use of an actuating device 2' of the type disclosed is notessential, as various forms of actuating devices may be employed withoutdeparting [from the principle or spirit of the invention.

Also the number of impression members on the plunger may be'varied,provided that,

in the case-of the use of an indented broken or interrupted (serrated)impression edge, a

plurality of at least two teet or projections of different depths beemployed so that the deeper the penetration the ater the. number ofimpressions made, or, m the case of the use of elther a broken orcontinuous impression edge, the construction be such that the broken orcontinuous line given will vary as to length as well as to depth ingauging materials of two or more relatively different degrees ofhardness.

. In practice the parts may be so constructed and adjusted as to operateon any recognized scale system for etermining hardness of materials, orto operate on any arbitary scale system established by the user or in a'shop for determining the relative degrees of hardness of the same ordifierent materials within certain limits. Thus, for instance, thedevice may be'constructed and used for determining whether two or morevarying pieces of the same kind of material, '1. e., hard and softaluminum alloys, are of the groper relative degrees of hardness forspecied uses without treatment, 'or come within 4 certain tolerationlimits, or are too hard or too soft with respect to such limits, andmust be re ected, or whether material in use, as v 1 of material withregard to relative hardness, and as an example a third material, in thesame class as the two before mentioned, may be standard aluminum.- Withthe par.- ticular device'disclosed it may be assumed that the plunger,sprin and sleeve are adoy by tooth llat a certaindegree of pressure, andfor penetration'of a softer aluminum alloy by the teeth 11 and'13 at thesame degree of ressure, and for penetration of iusted for penetration 0:a hard alumnium alstandard a uminum 'by all the teeth 11, 12

and 13 at such degree of pressure; The' device will thus indicate to theoperator by the number of impressions made'and length of the indentedline produced, or depth of the indentations or impressions, or both,whether or not the material tested is hard, medium" or soft according tothe determined scale or relative nature 015 the materi 21s.; The man inthe stock room of a factory may,

therefore, easily and quickly tell whether the material he is handin outis a hard aluminum alloy, a soft aluminum alloy or standard aluminum,and a workman who'is called upon to make small parts out of scraps ofsheet or tube material of the same general appearance may determinerapidly just what the difierent pieces are. An inspector may "also testthe parts after assembl into a finished airplane, which is impossilewith an ordinary testing machine.

Fig. 4 shows the result of a test made in which a single indentation 11'of minimum depth or the smallest degree of penetration by the tooth 11of the plunger has been formed inthe material, indicating that thematerial is hard within the test range of the tool. Fig. 5 shows theresult of a test made in which the penetrating surface of the plungerhas entered the material to a deeper extent and three indentations 11'and 13 have beenformed by the teeth 11 and 13, indicating that thematerial is medium within the range of the tool; Fig. 6 shows the resultof a te'st made in which the penetrating-surface of the plunger hasentered the material to its deepest or maximum extent and fiveindentations 11,"12' and 13' have been formed by the teeth 11, 12 and13,

indicating that the material is soft within the test range of the tool.It will beobserved that the variations of hardness are here indicatednot onl by the ion h of the broken or indented nejprodu and by number(1, 3 or 5) indentations but also by variations in depthoftheindentations, Ob- 5 viously instead of five teeth three only needbe used for via three difierent hardness-- indications, ut t enumber andarrange ment of teeth shown is preferred for various reasons. a Whilereference has been made only to the use of the device ior testin hardand soft aluminum allo. and stan ard aluminum, it is to be an erstoodthat the device may be em loyed with equal advantages for testing 0 ormaterials or for checking u the hardness of a materiel during di mentofmanufacture, as in the difierentr stages of metal rolling. The devicemay also be used in spinning, drawing, etc. to. 59 assure that thecondition of the material is within the roper limits of hardness.

It will {550 be ungerstood that 1the dimpression p un ers'an nn emp eyein thisdevice mfy be of idterch zngeable charactor, or standardized, sothat certain combinations of plu rs and springs will cover, certainranges o hardness. Standard test blocks of known hardnessmight befurnished with each combination so that the 39 adjusting bushing. couldbe properly set and left permanently at that setting. In this device theimpression points or teeth on the plunger or impression member I extendonly a very short distance. beyond the bottom face of the jaw 6, so thatwhen the work is squeezed between the jaws in testing the plunger movesonly a very short istance, ensuring a very long life of spring. Animportant feature of the device is that no matter how much excesspressure is brought to "bear on the tool handles, the load on theplunger is always constant, since any excess pressure on the handlessimply comthe work tighter between the jaws ut cannot increase the loadon the plunger, which is determined by spring'adjustment. A very simpleand accurate type of device may therefore be produced at a very lowHaving thus fully described my invention,

I claim 1. A hardness testing device of the character described having aplurality of impression members movable in a direction toward and fromthe material to be tested and terminating in difierent planesperpendicular to the direction of movement, said members being operativefor indicating by the number of said members penetrating a piece ofmate- 69 rial the hardness of the material with respect to a material ofgreater or less hardness, and

means for actuating said members with relation to the material whosehardness is tobe C3. 2..A hardness testing device of the characterdescribed having a plurali of con- A jointly movable im ression teeth 0difierent efiective len an operative for indicating by the num r of saidteeth penetrating a piece of material and their degree of pene- 7tration thereof the hardness o hardness, and means for actuating saidimpression teeth with relation to the material whose hardnessistobetested.

3. 'A hardness testing device of the chai acter described comprising aplurality of conjointly movable impression teeth having their materialentering ends extendi 'on a curved-line so as to terminate at di erentelevations with relation to each other and operative for indicating bythe number thereof penetrating a piece of material the hard ness of thematerial with respect to a material of greater or less hardness, andmeans for a'ctuating saidteeth with relation to the material whosehardness is to be tested."

4. A hardness testing device comprising an impressionmember having aplurality of enetrating projections of difierent efiective lenigthsoperative for indicating b number an depth of impressions formed erebyin V a p1ece of material the hardness of said mateme] with respect toamaterial of greater or less hardness, and means for-actuating said imression member.

a 5. A ardness testing device comprising'an impression member having apenetrating edge portion curved and indented so as to provide aplurality of alined impression members of different eflective lengthsand operative for penetrati a piece of material to different degrees forindicating the hardnes of said material with respect to a material ofgreater or less hardness, and means for actuating said impressionmember. a v 6. A'hardness testing apparatus embodying a sup rt for'thematerial to be tested, a support or an impression member, an impressionmember carried by the latter-named support and having a plurality ofteeth of different efl'ective lengths and operative for indicating bythe number of said teeth penctrating the material and their degree ofpenetration the hardness of said material with respect to a material ofgreater or less hardness, and means for moving said supports toward andfrom each other.

7. A hardness testing apparatus embodying a support for the work, a'support for an impression member, an impression member carried by thelatter-named support and provided with a plurality of impression teeth cof different effective lengths projecting therefrom and adapted to sinkto different depths in the material for indicating difl'erent degrace ofhardnem thereof, a spring for backing said impression device, means forvarying the load on the spring, and means for 0 v the material v withrespect to a material of greater or less adjusting the supports towardand from each other.

8. A hardness testing device comprising a support for the work, asupportfor an unpression plunger, animpression plunger carried by thelatter-named support and provided with a plurality of impression teethof different efiective lengths projecting therefrom, a spring forbacking said plunger, means for regulating the resistance of the springto recession of the plunger, and means for moving said supports towardor from each other.

9. A hardness testing device comprising ivotally connected actuatinghandles, parale1 motion jaws pivoted thereto, one of said jaws forming asupport for the work, an impression plunger carried by the other jaw andprovided with a plurality of impression 1 means for regulating theresistance of the tested and their extent of pentration the.

teeth of difierent efiective lengths projecting therefrom, a springbacking the plunger, and

spring to recession of the plunger.

10. A hardness testing device of the char acter described having animpression member movable toward and from a surface of a piece ofmaterial to be'tested and presentin penetrating projections terminatinin di ferent planes perpendicular to the lirection of movement, saidprojections being operative for indicating by the number of saidprojections penetrating the material to be degree of hardness of thematerial with respect to a material of greater or less hardmess. Y

In testimony whereof I afiii m si nature.

ROBERT A. W BS ER.

